Knowing how to distinguish the difference between a tie, slur and phrase mark in music will make it possible for you to play music effectively. While all three symbols look exactly the same, they can be identified by looking at the characteristics of the underlying music. Learning how to tell the difference will require an understanding of how each symbol appears and affects the music.
A tie looks like a curved line that attaches two notes together. Ties will never connect more than one note at a time; knowing this will make it possible for you to identify the difference between a tie and the other similar markings. When a tie appears, it means that you need to add the values of two notes together to create a longer value. For instance, a crotchet would normally be worth one beat. But if you tie that crotchet to another one you will now have to hold it for two beats.
Slurs will commonly appear over more than one note as a curved line similar to a tie. It can be difficult to tell if you are looking at a slur or a phrase marking. Some of the best musicians are confused by these markings. Slurs will appear only over a few notes, and not the entire melody. When you see a slur, you need to avoid articulating any of the notes that fall under it in order to play a technique called legato. This makes the music sound smooth and connected.
Phrase markings look just like slurs; however, they extend the entire range of the melody. A phrase marking will be identifiable if the curved line goes over the entire length of a melody that would be too long to sing in one breath. Generally, phrase markings are not used, since they can be too easily confused with a slur. Instead, some composers opt to use breath marks, which look like apostrophes, to indicate the end of a phrase.
Another type of slur worth noting is one that appears in string music. When you see slurs or phrase markings in string music, it indicates that the entire passage should be played with a single movement of the bow, from one end to the other. Basically, this means that the player must coordinate her timing on the bow to ensure that all the notes under the slur are played before she reaches the tip or frog of the bow, depending on what end she began with. Each time a new slur appears, it indicates to the string player to change the direction of the bow.